Volume 21, Issue 3 (July 1976)
Detection of Gunshot Residue by Use of the Scanning Electron Microscope
Current methods used to determine whether or not an individual has fired a handgun are based on analyses of samples taken from various regions of the hand for total content of antimony, barium, and often lead. High amounts of these elements are considered to be characteristic of gunshot residue [1–11]. However, the ability to identify residue conclusively has been severely restricted by the environmental occurrence of these same elements. Results of the studies described in this paper indicate that, by combining information about the morphology of gunshot residue particles with elemental analysis of individual particles [obtained by using an X-ray analyzer with the scanning electron microscope (SEM)], it is possible to reach a conclusion of increased significance concerning the presence of residue as distinguished from environmental contamination. The results of extensive studies of residue particles and analyses of numerous hand samples are presented here. It has become apparent that the new technique is a major improvement and that it is moderately rapid when performed by a trained microscopist.